The purpose of this graduate student research study is to compare the effects of low-load blood flow restriction training (LL-BFR) and heavy-load training (HLT) in high-volume rowers with mild low back pain or recurrent low back pain (LBP), aiming to determine whether LL-BFR offers a safer yet equally effective alternative to HLT for enhancing performance and reducing risk of re-injury.

Rowers will complete a web-based survey administered via administered via Google Forms for up to 15 minutes. Questions will address demographics, attendance adherence to rowing practice/races, a blood flow restriction pre-screening questionnaire, and the Orebro Musculoskeletal Pain Questionnaire (OMPQ) for LBP. Rowers will participate in a 2000-meter indoor rowing ergometer time trial to assess, technical fatigue, muscular fatigue, and performance. Muscular fatigue will be assessed through the use of Electromyography (EMG) collected via Noraxon Ultium electrodes and sensors on the hamstrings and quadriceps. Performance on the 2000-meter time trial will be determined by improvement of time to completion. Performance will be further assessed through a 1-repetition maximum (1RM) test for squat and deadlifts. Strength and endurance ratios will also be collected assessing hamstrings: quadriceps using an Asani tension dynamometer and abdominal endurance. Rowers will then be split into two groups (exercise and sham) through blocked randomization: light-load blood flow restriction training (LL-BFR) and heavy load training (HLT). Each LL-BFR session will include the following strength exercises at 20-30% of each participant's 1 RM: (1) Squats (Goblet/Back squat), (2) Deadlifts (Conventional/Romanian), (3) Side planks, (4) Plank, and (5) Bird-Dogs. The exercises will follow a 4-set structure: Set 1 with 30 repetitions, followed by three sets of 15 repetitions, with 30-second rests between each set. Participants will report their rating of perceived exertion (RPE) on a 1-10 scale, aiming to maintain an RPE of 7-8; load and occlusion pressure can be adjusted accordingly. The HLT will participate in the same exercises but under a different dosage of 6 sets and 5 reps at 60-80% 1 RM.

Inclusion Criteria:

• Aged 13-20 years old
• Currently active rower (training ≥3 days/week or 12 hours/week)
• Mild LBP with a low reactivity (<3/10) or recurring LBP within the past 18 months that has affected attendance to team practices/races.
• Able to complete a 2,000-meter rowing erg test

Exclusion Criteria:

• Have severe or acute back pain that limits basic movement or requires medical treatment
• History of spinal surgery or structural spine conditions (scoliosis requiring bracing/surgery)
• Have a contraindication to BFR training, identified via BFR safety screening form:
• Peripheral vascular disease (PVD)
• History of vascular surgery in arms or legs
• Skin grafts on arms or legs
• Arteriovenous fistula in limbs
• Cognitive or physical impairment that limits participation
• Hypertension or high blood pressure (uncontrolled or undiagnosed)
• Bleeding disorders (e.g., hemophilia)
• Blood clotting disorders (e.g., lupus, factor-V Leiden)
• Past history of DVT or pulmonary embolism (PE)
• Surgery in the past 12 weeks
• Recent limb immobilization (e.g., cast, boot) in the last 4 weeks
• History of stroke or transient ischemic attack (TIA)
• History of cancer
• Diagnosed heart disease
• History of rhabdomyolysis
• Diagnosed diabetes
• Sickle cell disease
• History of compartment syndrome
• History of nerve damage or injury
• Any prior complications or adverse reactions to BFR training
• Any other medical conditions that should be cleared by a physician before starting BFR
• Pregnancy(Self-reported)

We are not decided yet.